Question

Sue took a test in both biology and math last week. The biology test had a mean of 70 and a standard deviation of 7 whereas the math test had a mean of 75 and a standard deviation of 10. Sue scored a 76 on the biology test and a 76 on the math test. On which test did she do better in comparison to the rest of the class?​Select one:a. she did the same on each testb. the math testc. the biology testd. cannot be determined

Answer 1

c. the biology test

Explanation:

To answer this problem we need to calculate the z-score of both tests, using the formula:

z = (x - μ) / σ

Where x is Sue's score, μ is the mean, and σ is the standard deviation.

• For the biology test, the z-score is:

z = (76 - 70) / 7 = 6/7 = 0.857

• For the math test, the z-score is:

z = (76 - 75) / 10 = 1/10 = 0.100

Because the z-score for the biology test is greater than the z-score for the math test, Sue did better in the biology test, in comparison to the rest of the class.